Potential-regulator.



No. 788,278. A PATENTED APR. 25, 1905. E. H. PORTER & B. OURRIER. POTENTIAL REGULATOR.

APPLICATION FILED 00T. 7, 1904.

O'O'O'O'WO A TTORNE l.

UNITED STATES Patented April 25, 1905.

PATENT OFFICE.

EDWIN H. PORTER AND BURLEIGH CURRIER, OE PHILADELPHIA, PENN SYLVANI A.

POTENTIAL-REGU LATOR.

SPECIFICATION forming part of Letters Patent No. 788,278, dated April 25, 1905.

Application filed October 7, 1904:. Serial No. 227,520. I

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Be it known that we, EDWIN H. PORTER and BURLEIGH CURRIER, citizens of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Potential-Regulators, of which the following is a specification.

Our invention relates to commercial alternating-current generators, and particularly to means for maintaining a fixed Apotential at the terminals of the said generators.

The object of our invention is to provide an automatic regulator for an alternating dynamo which shall automatically maintain a constant alternating potential at the terminals ot' the dynamo or a potential of a predetermined rise or fall regardless of the current or load and speed of said dynamo. Regulators, both mechanical and electrical, have been designed to accomplish this purpose with more or less success. These have all had various defects, such as sluggishness, tendency to race, sparking contacts, and complicated construction, etc. IVe have endeavored to avoid these dililiculties and construct a regulator of simple form and of great reliability and accuracy.

Our invention contemplates using the standard alternators and exciters of modern practice and regulating the iield strength of either exciter or main dynamo by inserting a unidirectional current of electromotive force in series with either field-circuit in such a manner as to either add to or depress the electromotive force and current in said held-circuits, and therefore add to or depress the electromotive force of the alternating generator to 1 maintain it practically constant.

Throughout the specification the words electromotive force are abbreviated to E. M. E. and "direct current to 1). C.

Referring to the drawings, Figure I is a diagrammatic view showing our regulator and a generator, exciter, and transformers used in connection therewith. Fig. Q isa diagrammatic view showing the regulator connected with a different arrangement of coils.

In the drawings, Gr represents an alternating-current generator supplying the main ci rcuit M. The generator Gr has a field-circuit F supplied by an exciter-dynamo E, whose iicld-circuit is F. The control of the potential o'll the alternating generator Gr is accomplished by the variation ot' the strength of the exciting-current iiowing in the main field-circuit F. The variation ol' this main excitingcurrent is accomplished either directly or by the variation of the strength ot' current llowing in the lield-circuit E ot' the exciter-dynamo. It is well known in the art that the alternating potential ot the generator can be controlled by varying' the lield strength of either the exciter-dynamo E or the lield strength ot' the generator itself by varying the strength ot current iiowing in either. Ie then employ an alternating E. M. F. and current supplied from the terminals of the generator to be regulated. This may be either supplied direct or through suitable potential-transformers. This currentis supplied through the rectiiier in series with the I). C. licld-circuit. The E. M.. F. and strength of this current is varied by the movement of a laminated core with inductive relation to coils through which the current is flowing be't'ore being' rectified in response to variations of the potential oil the main generator-circuit to be regulated.

An induction-regulator is shown at I and consists of the primary coil P, connected in the circuit M, and the secondary coils l( and K, located at either end of the primary coil. The three coils oil the regulator are provided with a hollow cylindrical interior, in which is suspended a laminated core Ii, counterbalanced so as to move Ylreely within said coils in response to variations in the strength ot' the current flowing in the primary coil P. It will be readily.understood that as the core moves with inductive relation to the secondary coils l( and K the E. M. F. of one coil is increased at the same time the E. M. I?. in the other coil is decreased. The current from the coils K and IC of the regulator is carried through the medium of the transformers T T T2 T to the alternating-cm'rent rectifier, more liully described in another application. The rectifier consists of a stationary armature A ot' a synchronous motor having a revolving field R. The generator G through the circuit M supplies the motor-armature A with an alternating-current, also the current to be rectified.

The connnutator() is carried bythe revolving field R of the motor and is composed of bars B B2 B;i B4 and so on separated by insulating material c. The commutator-bars are arranged in pairs, as B and B2 or B:i and B", having permanent connections between them. Stationary brushes 1 2 3 4 and so on are in working contact with the commutator C. As the commutator-bars are arranged in pairs, they will short-circuit any two of the brushes successively as the comrnutator revolves.

The field B, carrying the commutator C, is supplied with a direct current from the exciter-dynamo E through the circuit F2, which circuit F2 is provided with collector rings and brushes. (Not shown.)

The current and E. M. F. from one coil K is led to transformers T and T and that from' the secondary coil K is led to transformers T2 and T3. The primaries F F2 and P: PL of each pair of these transformers are in series. The secondaries S and Szof' onepair are led to brushes 1 2 3 in such a manner that theE. M. F. of one opposes that of the other, so that their resultant sum is Zero. Similarly, the secondaries S and S" of the other pair are led to brushes 4 5 6 in sucha manner that theirE. M. F. oppose each other and their resultant sum is Zero. The commutator-bars B B2 Bi and so on revolving1 synchronously alternately short-circuits the E. M. F. of one coil or the other of each pair of secondary coils at the brushes l 2 3, also at the brushes 4 5 6, so that a unidirectional E. M. F. is maintained between brushesl and 2, also a unidirectional E. M. F. is maintained between brushes 4 and 6. The secondaries of the pairs of transformers T T and T2 Tl are relatively connected so that the unidirectional E. M. F. between brushes 1 and 3 is opposite to and opposes that between brushes 4 and 6, so that when they are equal their resultant sum is Zero. It will be readily seen that when the E. M. F. in transformer Tand T is greater or less than the E. M. F. in the transformers T2 and T3 the sum of the unidirectional E. M. F. is not zero, buteither a positive or negative quantity, according to the direction ofthe E. M. F. predoininating. Then either alternating E. M. F. is varied relative to the other by movements of the laminated core L, the E. M. F. resultant from the two pulsating' unidirectional E. M. F. s is made to add to or depress the E. M. F. of the current flowing in the circuit, and therefore in the field-circuit F and F. It is therefore clear that as the core L moves in response to variations in the E. M. F. and current in the coil P, due to the generator Gr, the resultant unidirectional E. M. F. between brushes 1 and the generator G. If the core L is properly counterlmlanced, the movement of the core L through its entire range required can be brought about by a very slight variation of' the E. M. F. of the circuit M, and the counterbalancing of the core can be arranged so that a given variation of' the main circuit E. M. F. applied to coil P will produce a greater or less change in E. M. F. in circuit F at either extreme position of the core L, as desired, thus producing either an increasing change in excitation of the machine throughout the entire range of the core L or a decreasing change, as desired.

Fig. 2 shows asimilar arrangement, except that the regulating E. M. F. is applied direct to the coils that are used as secondaries in Fig. 1, the primary I of' Fig. 1 being' omitted.

As the total E. M. F. applied to the terminals of the two coils K and K', Fig. 2, in series from circuit M varies, the position of the core L with relation to the two coils changes and the relative voltage drop through the two coils changes also. As the voltage of coil K or K predominatcs, the voltage through the rectifier applied to the D. C. exciting-circuit varies, as shown in Fig. 1, and regulates thc E. M. F. of the circuit M in the same manner.

In Fig. 1 the commutator of bars B B:i Bl and so on is shown mounted on the revolving field-frameof the synchronous motor R A. This field-frame can be excited from any convenient source of direct current, such as the exciter E. The armature Aof the synchronous motor is shown as stationary and is excited from the source of alternatingcurrent to be rectified. The brushes 1 2 3 and 4 5 6 are stationary. Any desired number of' bars and brushes can be utilized, giving due regard to the synchronousspeed required. In Fig. 1 only a few brushes are shown connected, it being evident that more brushes on the same commutator can be connected in, if desired.

lt will be understood that different mechanical arrangements of our regulator can be made without departing from the true spirit of our invention.

lV hat we claim as new, and wish to protect by Letters Patent, is-- 1. The combination of a direct-current fieldmagnet circuit, a source of alternating' electromotive force dependent upon said directcurrent field-magnet circuit, means for translating said alternating electromotive force into two unidirectional pulsating electromotive forces of opposite sign, means for connecting said unidirectional electromotive forces in series with said direct-current field-magnet circuit, and means for automatically varying one or both ofthe opposing electromotive forces in response to variations in said alternating electromotive force.

2. The combination of' a direct-current field- 6 varies and regulates the field strength of 1 magnet circuit, a source of alternating elec- IOO IIO

trornotive force dependent upon said directcurrent field-magnet circuit, means of deriving a plurality of alternating electromotive forces of differing phase relation from said alternating electromotive forces, means of connecting said different-phased alternating electr-omotive forces in series with said direct-current field-magnet circuit, a synchronously-revolving commutator arranged with brushes to short-circuit synchronously all electroniotive forces of other than one sign, and means for regulating the resultant unidirectional electromotive force in response to variations in said alternating electromotive force by regulating automatically the alternating electromotive forces and current applied in series with said field-circuit.

3. The combination of a direct-current lieldmagnet circuit, a source of alternating' electromotive force dependent upon said directcurrent field-magnet circuit, means for translating said alternating electrornotive force into a plurality of unidirectional electromotive forces of opposite signs Whose algebraic sum is zero, and means for automatically varying some or all of said unidirectional clectromotive forces so that their algebraic sum is greater or less than Zero in response to variations in said alternating electrornotive force said unidirectional electromotive force being in series with said direct-current field-magnet circuit.

4. The combination of a direct-current fieldmagnet circuit, a source of alternating electrornotive force to be regulated dependent upon. said direct-current Held-magnet circuit, a rectifier having brushes and commutator in series with said direct-current field-magnet circuit, said rectifier connected to said source of alternating electromotive force through transformers and an induction-regulator automatically responsive to variations in said alternating electroinotive force, said rectilier and transformers arranged so as to provide two or more independent circuits through it for the direct-current field-current.

The combination in avoltage-regulator, of a direct-current iicldmagnet circuit, a source of alternating electromotive force dependent upon said lield-circuit, a plurality of pairs of transformers whose primaries receive current from said source of alternating electromotive force through an induction-regulator responsive automatically to variations in said electromotive force, primaries of each pair of said transformers being in series; secondaries of each pair of transformers joined in series and in series with said direct-current field-circuit and joined to pairs of brushes in opposition, so that the electromotive force of each pair at the brushes is Zero; a commutator of a plurality of insulated bars arranged with brushes to short-circuit one electromotive force of each pair of secondaries synchronously in succession.

6. The combination of a direct-current lieldmagnet circuit F, an alternating-current main circuit M, transformers T' T2 T3 T", inductionregulator I, commutator C, or bars B B"2 B B1, &c., asynchronous driving-motor for said commutator, all arranged connected together and for the purpose substantially as set forth.

In testimony whereof we afiX our signatures in presence of two witnesses.

EDVIN H. PORTER. BURLEIGH CURRIER. Vitnesses:

WM. A. ALLIsoN, XVM. R. STAcKi-rousn. 

